​Summary: Evidence is limited as to whether the introduction of the Affordable Care Act (ACA)'s Medicaid expansions was associated with improvements in cardiovascular risk factors at the population level. Authors examine the association between the ACA Medicaid expansions and changes in cardiovascular risk factors among low-income individuals during the first three years of the implementation of the ACA Medicaid expansions at the national level.

Authors utilized a quasi-experimental difference-in-differences (DID) analysis to compare outcomes before (2005–2012) and after (2015–2016) the implementation of the ACA Medicaid expansions between individuals in states that expanded Medicaid and individuals in non-expansion states. The study consists of a nationally representative sample of individuals aged 19–64 years with family incomes below 138% of the federal poverty level from the 2005–2016 National Health and Nutrition Examination Survey (NHANES). Cardiovascular risk factors included (1) systolic and diastolic blood pressure, (2) hemoglobin A1c (HbA1c) level, and (3) cholesterol levels (low-density lipoprotein cholesterol, triglyceride, and high-density lipoprotein cholesterol).

Summary: A total of 9,177 low-income individuals were included in this study. Authors found that the ACA Medicaid expansions were associated with a lower systolic blood pressure and lower HbA1c level. They found no evidence that diastolic blood pressure and cholesterol levels changed following the ACA Medicaid expansions.

Using the nationally representative data of individuals who were affected by the ACA, authors found that the ACA Medicaid expansions were associated with a modest improvement in cardiovascular risk factors related to hypertension and diabetes during the first three years of implementation.